Dispenser packages are known that include a plurality of flexible sheets each comprising a layer of pressure sensitive adhesive on a backing, which sheets have first and second ends and are adhered to each other in a stack with the first and second ends of successive sheets in the stack adjacent, and have first end portions adjacent their first ends that are not adhered to (or can be easily separated from) the underlying sheet in the stack to facilitate removal of the uppermost sheet in the stack.
U.S. Pat. No. 5,086,946 describes such a package including such a stack of sheets in which the layers of pressure sensitive adhesive extend over the entire backings on the sheets, and the separation of the first end portions of the sheets is afforded by the use of release means for providing a first low adhesion level along the first end portion of each of the sheets between the layer of adhesive and the surface of the adjacent sheet in the stack to which the layer of adhesive is releasably adhered, and attachment means for providing a second adhesion level along a second end portion of each of the sheets adjacent their second ends between the layer of adhesive and the adjacent sheet in the stack that provides a release force that is higher than the low release force along the first end portion.
U.S. Pat. No. 4,770,320 describes such a dispenser package including such a stack of sheets (that are commercially available from Minnesota Mining and Manufacturing Company, St Paul, Minn. under the trade designation "Post-it (T.M.) Brand Tape Flags") in which the layers of pressure sensitive adhesive extend over only a portion of the backings for the sheets. While each of the dispensing packages described in these U.S. Patents is effective, both utilize shuttling of the stack to dispense the sheets.
U.S. patent application Ser. No. 08/263,601, filed Jun. 21, 1994, the content whereof is incorporated herein by reference, describes a simple dispenser package for stacks of sheets of the types described above that does not require shuttling of the stack to dispense the sheets, thereby affording a reduced length for the dispenser package compared to dispenser packages in which the stack of sheets shuttles as sheets are dispensed. That dispenser package can include a stack of flexible sheets generally of the type described in U.S. Pat. No. 5,086,946, or generally of the type described in U.S. Pat. No. 4,770,320, each of which sheets has first and second ends and comprises a backing having a layer of pressure sensitive adhesive on a bottom surface by which the sheets are releasably adhered to each other in the stack with adjacent ends of the sheets aligned and with first and second ends of successive sheets in the stack adjacent. The sheets include either (1) release means for providing a first low adhesion level along a first end portion of each of the sheets adjacent its first end, which first adhesion level provides a low release force between the layer of adhesive and the adjacent top surface of a sheet to which the adhesive is releasably adhered, or (2) means for preventing adhesion of the first end portions of the sheets to underlying sheets in said stack; and attachment means for providing a second adhesion level along a second end portion of each of the sheets adjacent its second end between the layer of adhesive and the top surface of the adjacent sheet in the stack that provides a release force that is higher than the low release force (if any) along the first end portion and firmly adheres the sheet to the adjacent sheet in the stack while affording peeling the sheet from the stack along its second end portion. The first end portions of the sheets have lengths from the first ends toward the second ends of the sheets that are shorter than half the lengths of the sheets so that centered portions of the layers of pressure sensitive adhesive between the first end portions of successive sheets in the stack releasably adhere the sheets in surface to surface relationship in the stack. That dispenser package includes an enclosure comprising walls defining a chamber in which the stack of sheets is positioned. Those walls include (1) a bottom wall defining a bottom side of the chamber, (2) two top wall portions defining a top side of the chamber opposite the bottom side and having, (either initially or after the package is opened) spaced opposed first and second abutment surfaces extending generally parallel to ends of the bottom wall, which abutment surfaces define a wide generally central transverse slot having a length between the abutment surfaces that is about equal to or greater than the length of the centered portions of the layers of pressure sensitive adhesive; and (3) side walls between the top wall portions and the bottom wall. The stack of sheets is positioned in the chamber with the ends of the sheets generally parallel to the ends of the bottom wall, and the lowermost sheet in the stack adjacent the bottom wall. The dispenser package includes means for restricting endwise movement of the stack relative to the housing and means for restricting flexing of the second end portions of all but the uppermost sheet in the stack around an axis parallel to the ends of the sheets in the stack (which means can be provided by adhering the lowermost sheet in the stack to the bottom wall or including a stiff support sheet within the chamber adjacent the bottom wall to which the lowermost sheet in the stack is adhered); and one of the abutment surfaces is disposed with respect to the uppermost sheet in the stack so that the first end portion of that uppermost sheet can project through the slot and rest against that one abutment surface. The length of the slot between the abutment surfaces affords, as the uppermost sheet is pulled through the slot by its first end portion, peeling of successive portions of the uppermost sheet from the first underlying sheet in the stack to which the uppermost sheet is adhered, and then separation of the first end portion of the first underlying sheet from the second underlying sheet, and movement of the first end portion of the first underlying sheet through the slot with the second end portion of the uppermost sheet to leave, after the uppermost sheet is fully peeled from the first portion of the first underlying sheet, the first end portion of the first underlying sheet in a position projecting through the slot and resting against the second abutment surface and disposed in a position where it may be grasped for manual removal in a manner similar to the removal of the uppermost sheet.
U.S. Pat. No. 5,158,205 describes an inexpensive dispenser for a small stack (e.g., less than 100 sheets) of similarly sized sheets of note paper (e.g., a stack of note paper that is commercially available from Minnesota Mining and Manufacturing Company under the trade designation "Fan-folded Post-it (.TM.) Brand Note Pad for Post-it (.TM.) Pop-up Note Dispensers) of the type each having a narrow band of adhesive coated on its bottom surface along one edge by which the sheet is adhered to the top surface of the adjacent sheet in the stack with the sheets being stacked with the band of adhesive of adjacent sheets at alternate opposite sides of the stack. The dispenser comprises a housing closely receiving the stack, which housing includes a top wall comprising a single layer of flexible material adjacent a top surface of the stack. The top wall has spaced edge surfaces extending between flanking slits that define two opposed flap like portions of the top wall and a slot through the top wall between the flap like portions, through which slot projects an end portion of the uppermost sheet in the stack. When the uppermost sheet in the stack is withdrawn through the slot, the flap like portion adjacent the band of adhesive on the uppermost sheet will flex away from the stack to form a convex arcuate surface adjacent the stack along which the sheet being withdrawn and the end of the second uppermost sheet in the stack to which the band of adhesive is adhered can slide to thereby restrict curling of the sheets, and the flap like portion opposite the band of adhesive on the withdrawn uppermost sheet will place drag on the second uppermost sheet in the stack so that the force applied to withdraw the uppermost sheet will peal the uppermost sheet away from the end of the second uppermost sheet in the stack after it is withdrawn through the slot rather than fully withdrawing the second sheet through the slot.